ExRx.net

Let's say there are two guys of the same age, height, level of experience in the gym and both are measured in the healthy range on all charts including cardio.

Person A weighs 158lb and has 22% body fat. Person B weights 139lb and 11% body fat.

Since they both have the same muscle mass of 123lb should they both have the same strength if they train the same?

No. It's more or less about the ability to recruit muscle fibers, and the firing sequence.
Also it could be possible that A is better at doing 50 squats, when B is crushing in 1RM squats.
Plus, they could have muscle mass, but do they have experience? That makes heaps of difference.

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Prove the impossible!

let me paly mediator

Let's presuem they are equal in experience and muscle recruitng abiliy and those other items above...

Does fat impact lifting, might be what OP is asking...

Yea thats it, with this hypothetical question you cannot consider other factors (i.e. both have the same ability to recruit fibres equally, they both "have experience")

I would say all that mattered would be the muscle mass in this example

The general trend towards fatter guys (but with equal muscle mass) lifting more is because at no point have they sacrificed growth for low body fat/leaness - I've asked the same before (at what point does it become quite useless to eat even more, i.e. will adding 100% more calories be worth the strength gains, vs just adding 15%)

But my personal answer is I don't know for sure - I would say, with your example, and no other variables considered, all that would matter is the muscle mass, since that is all that is doing the work.

In cases where the body is part of the load (squats, deadlift, pushups, pullups) the lighter weight guy has the clear advantage. For exercises where the body is not part of the load, the fatter guy has a slight advantage. The advantage is very slight but it is real. Partly it's due to improved leverages. There may be other reasons too. However, muscle is what produces force so most of the results come from the muscle.

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Let thy food be thy medicine, and thy medicine be thy food.~Hippocrates
Strength is the adaptation that leads to all other adaptations that you really care about - Charles Staley
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Thanks TimD

Huh? These guys are only composed of muscle and fat? Neither would be able to lift a stinking thing!

I understand the intent of your question, but do you really think that this is their muscle mass? What about bones? Abdominal organs? Brain? Ligaments and tendons? Hair? Fingernails? Skin, for goodness sake.

The mass of the body minus the fat is the "lean body mass", and it's quite a bit higher than muscle mass.

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Our greatest fear should not be of failure, but of succeeding at things in life that don't really matter.--Francis Chan

Alright, let's change the example.

Joe used to weigh 158lb with 22% body fat. He performs all the barbell exercises with good form.
Now Joe weighs 139lb with 11% body fat (losing 19lbs of fat).

Will he perform those exercises better, worse or the same as before?

That is a better example and intersting to me. THis is also a magic man losing 100% fat, but we get the point, maybe he trimmed even more and then bulked back to 139...
Also, can we discuss if it matters if we consider the opposite, starting @11%, then going to 22%.

At the instant, I'd say lift less at the lower fat just because we are probalby coming from weeks of energy defict, but lol, again, probaby not what you want to focus discussion on.

Presuming we get our energy up and all other paramaters are as even as possible, I'd go back to what Stu said, which is my default.

I think most people can maintain strength while losing fat, if they train hard, and lose slowly. It's easier to gain strength while maintaining or gaining weight, thus the common practice of cutting and bulking.

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Our greatest fear should not be of failure, but of succeeding at things in life that don't really matter.--Francis Chan

I think the better question is:

Given everything else as equal (muscle mass, muscle recruitment, etc.) would the fat guy be stronger? The answer is no.

or:

Given two identical people with identical potential traits, blah, blah guy, start at the exact same training point and have the exact same exercise regime, what would the difference in strength be? (in that case I'd say the fat guy has the advantage).

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Thanks TimD.

It can be same because they both have same muscle mass and height, so because of extra fat strength won't differ.

On my body fats I am losing % on most areas bar my lower back and sides. Any tips on helping with this?

What? Lose fat. That's it. There's no way to target any fat to burn.

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Prove the impossible!

Liposuction, ultrasound or a blowtorch, or if you're in PNG get in a fight with one of the locals with a machette.

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Let thy food be thy medicine, and thy medicine be thy food.~Hippocrates
Strength is the adaptation that leads to all other adaptations that you really care about - Charles Staley
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Thanks TimD

No way that doesn't make me jobless in the future that is. If people start to get into machete fights rather than exercise to lose fat, it would be the final straw for me.

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Prove the impossible!